The smell of rotting eggs has a Viagra-like effect on men, and the bizarre finding could help doctors develop a more effective version of the popular sex drug, according to a study.

The gas that gives rotten eggs their pungent smell is hydrogen sulphide. Scientists say it also is released from car exhausts and from men just before they have sex, according to the study published in the Proceedings of the National Academy of Sciences.

Tiny amounts of the gas are released by nerve cells in a man’s private part to prepare it for intercourse, a study found.

The gas causes muscle cells in the region to relax, boosting blood flow, and leading to a better erection.

Researchers, from the University of Naples in Italy, made the finding in a study of eight men who had sex-change operations.

Viagra, on the other hand, harnesses a different chemical – nitric oxide – to give users a boost.

But one-third of men have found the drug ineffective.

Researchers hope the finding will lead to new drugs to treat erectile dysfunction.

Click here to read more on this story from The Sun.

Click here to see the study published in the Proceedings of the National Academy of Sciences